and British 10th (Irish) Division at Kosturino reached the Greek border. At this point Vardar Macedonia was completely cleared of Entente presence but the Second Army several times received warnings from the Bulgarian High Command that any crossing of the Greek border was absolutely forbidden. This allowed the Allies to safely retreat to Salonika. For the entire campaign in 1915 the casualties suffered by the Second Bulgarian Army were 4,084 killed, 17,642 wounded, 999 dead from disease and 1,888 missing or a total of around 24,613. Macedonian front In early 1916 the Bulgarians and Germans agree to postpone any plans for an attack of Salonika and dig in along the border with Greece. The Entente used the time to reinforce and entrench around the town. Once it became evident that the Bulgarians were not going to advance the Allied forces themselves began moving up to the Greek border and by the end of May contact between the opposing forces was reestablished. The Bulgarian Second Army which took up position along the Belasitsa range now consisted of the 7th Rila, 11th Macedonian Infantry Division and the 3/2 Infantry Brigade. The 5th Danube and the rest of the 2nd Thracian Infantry Division had been assigned to the German Eleventh Army. Contact with the Allies in this part of the front was also reestablished. The Bulgarian High Command realized that if the Entente occupied the Southern exit of the Ruppel Pass and took the fortress there, the Second Army would not be able to advance south along the Struma and the threat of an Allied attempt to penetrate into Bulgaria itself would grow significantly. With this in mind, the 7th Rila Division was ordered to forestall these events by occupying Ruppel fortress first. On 26 May the Bulgarian forces crossed the border, meeting no opposition from the Greek border guards. By the next day the 7th Division was in complete control of the entire Ruppel Pass and now controlled all avenues of approach from Demirhisar to the valley of the Struma. As soon as the operation was over the Bulgarians began fortifying their new positions. The Bulgarian forces however still remained scattered and had to cover a front of almost 600 kilometers. On a line between Albania and Lake Dojran the Central Powers had arrayed the Bulgarian First Army and the German Eleventh Army (which consisted mostly of Bulgarian formations) under Army Group